1. Field of the Invention
The present invention relates to an instrument display apparatus and more particularly to such a device which is adapted to produce a reflected image of an instrument in a windscreen or other similar assembly such that an operator may view same while simultaneously viewing out through the windscreen.
2. Description of the Prior Art
The development of a head-up display (HUD) is relatively new and probably had its genesis in the military aircraft field. As should be understood and in the operation of high-speed aircraft, traveling in excess of the speed of sound, and particularly aircraft designed for combat maneuvering, it is extremely hazardous for the pilot to divert his attention from a point of interest in the vicinity of the aircraft to read the dials, gauges, instruments, warning indicators, etc., on the assorted instrument panels which are located in various positions about the cockpit but below his normal line of sight.
More recently this same problem has been recognized in the field of high speed motor car operation. Further, experts have speculated that this same technology could perhaps be helpful in the day to day driving activities of the average motorist.
In any vehicle application, however, one will recognize that employment of a HUD will enhance the safe operation of same because a HUD permits the operator of the vehicle to view, directly in his line of sight, critical instrumentation displays such as speed, fuel consumption, oil pressure, etc., without diverting his eyes from the area immediately in front of the vehicle.
The prior art is replete with numerous examples of heads up display devices. For example heads up display systems have been disclosed in several U.S. patents, particularly Steward U.S. Pat. No. 4,652,870; Banbury U.S. Pat. No. 4,560,233; Spooner U.S. Pat. No. 4,347,508; and Garner U.S. Pat. No. 4,453,163. Further the references cited in these same U.S. patents are pertinent but not as critical or relevant as are the above four patents to the instrument display apparatus of the present invention.
As interesting as the prior art may be, none of these references teaches or suggests the method and apparatus of the present invention wherein a substantially transparent windscreen is borne by an overland vehicle and which includes a predetermined tint field which attenuates preselected wavelength of light and which provides unrestricted viewing in all directions and which is combined with an instrument which is displayed adjacent to the windscreen and which produces light in the selected wavelengths which are attenuated by the tint field whereby the image of the instrument appears within the tint field.